System and Methods to Provide Lift to a Vessel

Abstract

A lift unit, a system of such units, and methods of using such systems for a vessel moving through a fluid, are disclosed for providing lift and for controlling roll, pitch, and heave of the vessel. Each lift unit includes a passageway with a constricted chamber, through which fluid flows. Disposed within each constricted chamber is a foil having an axle attached at two ends, controlling the rotation of the foil in the flow of fluid. As fluid flows through the constricted chamber, its velocity increases, causing the foil to exert a lift force. The magnitude of the lift force is controlled by controlling the rotation of the foil about the axle.

What is claimed is: 
     
         1 . A lift unit for providing lift to a vessel moving through a fluid, the lift unit including:
 a passageway configured to allow the fluid to flow within as the vessel moves through the fluid, the passageway including:
 a tapered chamber having a mouth with an inflow area at a fore end, configured for inflow of the fluid into the fore end through the mouth as the vessel moves through the fluid and an aft end opposite the fore end, the tapered chamber narrowing from the fore end toward the aft end; and 
 a constricted chamber having a fore end and an aft end, the fore end of the constricted chamber connected to the aft end of the tapered chamber, the aft end of the constricted chamber having an exit for outflow of the fluid, the exit having an outflow area which is less than the inflow area; 
   a foil situated within the constricted chamber, the foil having an axle about which the foil is configured to rotate, the axle having an outboard-side end and an inboard-side end, the axle being attached to the lift unit at the outboard-side end and at the inboard-side end; and   a drive mechanism disposed in a drive mechanism compartment, the drive mechanism connected to the foil and configured to rotate the foil about the axle so as to control the lift as the fluid flows through the constricted chamber.   
     
     
         2 . The lift unit of  claim 1 , wherein the constricted chamber and the tapered chamber overlap. 
     
     
         3 . The lift unit of  claim 1 , wherein the lift unit is retractable into a hull of the vessel. 
     
     
         4 . The lift unit of  claim 1 , wherein the foil is a hydrofoil, and the fluid is water. 
     
     
         5 . The lift unit of  claim 4 , wherein the drive mechanism is housed in a watertight compartment separate from the hydrofoil. 
     
     
         6 . The lift unit of  claim 1 , wherein the drive mechanism is rotatably connected to the axle. 
     
     
         7 . The lift unit of  claim 1 , wherein the drive mechanism is coupled to a rod which connects at an end of the foil away from the axle, the drive mechanism configured to move the rod in a linear direction so that the foil rotates about the axle. 
     
     
         8 . The lift unit of  claim 5 , wherein the watertight compartment is configured to hold oil. 
     
     
         9 . A system for providing lift to a vessel having a hull moving through a fluid, the system comprising:
 one or more lift units configured to be attached to the hull of the vessel, each lift unit according to  claim 1 ;   one or more motion sensors, disposed on the vessel, configured to monitor pitch, roll, and heave motions of the vessel; and   a motion control command unit (MCCU) configured to receive signals from the one or more motion sensors, the MCCU configured with a processor and instructions for control of the one or more lift units, based at least in part on the signals received from the one or more motion sensors.   
     
     
         10 . The system of  claim 9 , wherein at least one of the lift units is retractable into the hull of the vessel. 
     
     
         11 . The system of  claim 9 , wherein the one or more lift units includes a port lift unit and a starboard lift unit symmetrically disposed with respect to each other on the hull of the vessel. 
     
     
         12 . The system of  claim 9 , wherein the one or more lift units includes two fore lift units positioned on opposing sides at a forward location on the hull, two midship lift units positioned on opposing sides at a midship location on the hull, and two aft lift units positioned on opposing sides at an aft location on the hull. 
     
     
         13 . The system of  claim 9 , wherein the total number of lift units is three, and includes a single lift unit at either an extreme forward location on the hull, or an extreme aft location on the hull, close to a center line of the ship, and two lift units positioned on opposing sides at close to midship on the hull. 
     
     
         14 . A method of providing lift to a vessel having a hull moving through a fluid comprising:
 configuring the vessel with a system for providing lift according to  claim 9 ;   monitoring pitch, roll, and heave motions of the vessel with the one or more motion sensors;   transmitting signals related to pitch, roll, and heave motions of the vessel to the motion control command unit from the motion sensors;   receiving the transmitted signals from the motion sensors by the motion control command unit; and   based, at least in part, on the signals received from the one or more motion sensors, controlling the one or more lift units.   
     
     
         15 . The method of  claim 14 , wherein controlling the one or more lift units includes controlling attack angles of the foils disposed in the lift units. 
     
     
         16 . The method of  claim 15 , wherein controlling the attack angles results in a change in lift of the vessel. 
     
     
         17 . The method of  claim 15 , wherein controlling the attack angles results in a reduction in motions selected from the group consisting of pitch, roll, heave, and combinations thereof.